#include <Functions/FunctionFactory.h>
#include <Functions/FunctionsConversion.h>

namespace DB
{

const DateLUTImpl * extractTimeZoneFromFunctionArguments(Block & block, const ColumnNumbers & arguments)
{
    if (arguments.size() == 2)
    {
        const ColumnConst * time_zone_column = checkAndGetColumnConst<ColumnString>(block.getByPosition(arguments[1]).column.get());

        if (!time_zone_column)
            throw Exception("Illegal column " + block.getByPosition(arguments[1]).column->getName()
                + " of second (time zone) argument of function, must be constant string",
                ErrorCodes::ILLEGAL_COLUMN);

        return &DateLUT::instance(time_zone_column->getValue<String>());
    }
    else
        return &DateLUT::instance();
}


void throwExceptionForIncompletelyParsedValue(
    ReadBuffer & read_buffer, Block & block, const ColumnNumbers & arguments, size_t result)
{
    std::string message;
    {
        const IDataType & to_type = *block.getByPosition(result).type;

        WriteBufferFromString message_buf(message);
        message_buf << "Cannot parse string " << quote << String(read_buffer.buffer().begin(), read_buffer.buffer().size())
            << " as " << to_type.getName()
            << ": syntax error";

        if (read_buffer.offset())
            message_buf << " at position " << read_buffer.offset()
                << " (parsed just " << quote << String(read_buffer.buffer().begin(), read_buffer.offset()) << ")";
        else
            message_buf << " at begin of string";

        if (to_type.behavesAsNumber())
            message_buf << ". Note: there are to" << to_type.getName() << "OrZero function, which returns zero instead of throwing exception.";
    }

    throw Exception(message, ErrorCodes::CANNOT_PARSE_TEXT);
}


void registerFunctionsConversion(FunctionFactory & factory)
{
    factory.registerFunction<FunctionToUInt8>();
    factory.registerFunction<FunctionToUInt16>();
    factory.registerFunction<FunctionToUInt32>();
    factory.registerFunction<FunctionToUInt64>();
    factory.registerFunction<FunctionToInt8>();
    factory.registerFunction<FunctionToInt16>();
    factory.registerFunction<FunctionToInt32>();
    factory.registerFunction<FunctionToInt64>();
    factory.registerFunction<FunctionToFloat32>();
    factory.registerFunction<FunctionToFloat64>();
    factory.registerFunction<FunctionToDate>();
    factory.registerFunction<FunctionToDateTime>();
    factory.registerFunction<FunctionToUUID>();
    factory.registerFunction<FunctionToString>();
    factory.registerFunction<FunctionToFixedString>();
    factory.registerFunction<FunctionToUnixTimestamp>();
    factory.registerFunction<FunctionCast>();
    factory.registerFunction<FunctionToUInt8OrZero>();
    factory.registerFunction<FunctionToUInt16OrZero>();
    factory.registerFunction<FunctionToUInt32OrZero>();
    factory.registerFunction<FunctionToUInt64OrZero>();
    factory.registerFunction<FunctionToInt8OrZero>();
    factory.registerFunction<FunctionToInt16OrZero>();
    factory.registerFunction<FunctionToInt32OrZero>();
    factory.registerFunction<FunctionToInt64OrZero>();
    factory.registerFunction<FunctionToFloat32OrZero>();
    factory.registerFunction<FunctionToFloat64OrZero>();
}

}